Mixer



Patented Sept. 10, 1929.

UNITED. STATES PATENT OFFICE.

Application filed June 24,

My invention relates to high speed mixers adapted to produce emulsions of nonmiscible liquids or various mixtures and to produce instantaneous chemical .reactions.

5 It has for its object to produce a device of this kind which will create an intense circulation of liquids, the latter being submitted simultaneously to strong mixing effects and to laminating or thinning effects and/or to shocks. w

Another object of my invention is to increase the laminatin effects by the passage of the liquid or liqui s to be treated, through spaces of varying section according to the,

" conical curve I may make use of the known viscosity of the liquid or liquids.

A further object is to provide means whereby compounds which are to be incorporated insaid liquid according to the rections to be produced may be added during the mixing and also to secure means whereby any gases produced during the reactions can be expelled.

A still further object is to provide means whereby the heating or cooling of some parts of the apparatus is obtained during the work ing, so as to control the temperature at which the operations are carried out;

With these objects in view my invention essentially' consists in the special arrangel ments and combinations of parts hereinafter fully described and pointed out in the appended claims.

Referring to the drawings,

Fig. 1 is a longitudinal section through an apparatus provided with six cells. I s

Fig. 2 is a cross section taken through line II-II in Fig. 1.

Fig. 3 is a cross section taken through line IIIIII in Fig. 1.

by means of feet 2, the under part 3 of the body of the apparatus. This body is formed of two parts 3 and 6 divided in the horizontal plane passing through the axis of symmetry by a shaft 4 rotating in bearings 5 mounted onthe frame 1. The upper part 6 of this body can be raised, in a known manner, by means of a winch (not shown on the drawing) and swung upon hinges 6, like the lid of a box,

On these drawings, 1 is a frame supporting,

as shown on Figure 2. The two parts 3 and mxnn.

1927. Serial No. 201,052.

6 of the body form a multiplicity of chambers or cells 7 having a profile 8 traced as a curve adapted to be used as a directing surface in order to'direct the liquid firstly towards the periphery of the cell and afterwards with more or less resistance towards the centre of this cell in producing a whirl.

In the practical embodiment of my invention, this curve'may be a non-circular conical curve such as an ellipse, a parabola, a combination of an ellipse and a parabola, or a combination of a parabola and hyperbola, as shown in the drawing. By forming the direction surface in the shape of a non-circular Gil laws of reflection of these curved surfaces. For instance, in the case of a parabola, ma terial thrown against such a surface will be reflected from the surface substantially through the focus and thrown against another portion of the surface by the action of the stirrer from which it will be reflected away from the latter point in a direction substantially parallel to the original direction of the material. In the'case of combined curves, such as the parabola and the hyperbola, the parabolic section being on the inlet side of the cell, the material, as before, is reflected from the surface through the focus which is common to the hyperbola. The material is then thrown against the hyperbolic section from which it is reflected at an angle to the stirrer. By the angular reflection from the surface of the hyperbolic section, a horizontal velocity component is imparted to the material,- and the rate of flow through the mixer is increased. Thus, by proper selection of the curved sections, the rate offlow and intensity of mixing may be varied. The joining or partition wall between two adjacent cells 7 forms projections 9, which are cut so as to form an edge 10 which may be at varying distances 11 from the axis of the shaft 4 in the successive cells. Shaft 4 passes through the lateral walls of the body formed by the; two parts 3 and 6, and through stuffing boxes 12 at each end thereof to ensure tightness of the shaft. This shaft may be provided with a pulley 13. or an'y other driving means adapted to rotatethe shaft at a high speed.

In the adjacent succeeding cells, the shaft carries operating elements formed by discs 15,

both outer surfaces of which are convex.

i These discs may be'solid, as shown by way of example in the two last cells, on the right of the drawing or they may also be provided with holes 16 arranged along radiuses (Fig. 3). The diameters of these holes gradually increase as the holes approach the periphery, as shown on the drawing in the discs arranged in the two center cells. The walls 9 forming the edges 10 may be cut, or otherwise provided on their inner surface 17 with teeth 18 as shown (Figs. 1 and 2) for the wall comprised between the second and the third cell 7 shown on the drawing. These walls 9 may however also be provided with holes 19 the diameter of which is preferably increasing towards the periphery that is to say as the distance from the centre increases with respect to the centre of the shaft 4. Thebod formed by the two parts 3 and 6 is provided with second casing or jacket'20 forming two or more chambers 21 between the body proper and the outer casing which latter may be tapped to allow the entry of a. heating or a cooling agent.

" Certain cells 7 or allthe said cells may be provided with one or more radially disposed ducts 22 which pass through the double casing 20 and open at 23 in the cells, at varying distances from the centre of the shaft 4, so as to allow either the introduction in the cell of suitable compounds or reagents or the escape of the gases produced in the cells by the reactions.

The end walls 2-1 of the body of the apparatus are provided with inlet and outlet 0penings 25 and 26 respectively, one of which (the opening 25) arranged in the upper part of the body, is connected by a connecting piece 27 to the pipe conducting the liquid or liquids to be treated to the cells and the other (the opening 26) arranged at the under part of the body is connected to an outlet pipe 28 for carrying away the treated liquid.

During operation of the device shaft 4 carrying operating elements 14 and 15 and forming with the latter, a rotor, is rotated at a high speed by means of the pulley 13 or any other suitable driving means.

The liquid to be treated, flowing by gravity from a reservoir (not shown) or fed under a given pressure by means of a pump (not shown) is introduced through the connecting piece 27 and flows out through the outlet pipe 28, so that the circulation in the different cells takes place between the openings 25 and 26.

During the passage of the liquid through the different cells, it is subjected to the centrifugal action of the shaft and the operating elements of the rotor formed by the arms 14, and/or the son of the free spaces existing between the ex-.

treinities 29 of the discs 15 and the top of the arcs of parabolas 8. Moreover this thinning action is accentuated by the passage of the liquid along the edges 10 of the extremities of the walls 9, the distance from the edges to the shaft 4 being varied according to the viscosity of the liquid. The number of the cells, and the sectional curvature of the various cells is chosen in each case according to the effects to be obtained, in each cell separately and all of the cells combined, if chemical reactions, in which several reagents must successively take part must be effected, or if the products require successive enrichments in one or more reagents. These reagents may be introduced in one or more cells by the ducts 22 corresponding to the inlets 23. In the same manner, when the reactions result in the production of gas the latter can escape through the outlets 23 suitably arranged to that end. -Moreover, during operation, the temperature may be controlled in each cell or in a series of cells by means of the chambers 21 formed by the double Walls 20 in which a heating or cooling agent is introduced and put into circulation by any known means.

I am aware that a great number ofdevices or mixers based on the action of a rotor provided with arms or discs and rotating at high speed have already been suggested. In one of those mixers the rotor revolves excentrically with respect to the main chamber of the apparatus so as to constantly bring the liquids which have previously been treated back in the operative field of the rotor.

In other devices the rotor is formed by a shaft carrying a disc, the periphery of which forms a cylindrical or truncated surface so as to rotate opposite a concentric surface at a small distance from this latter and to produce a thinning action by the shorter or longer path of the liquid between these con centric surfaces. It has also already been suggested to provide the acting surface of the rotor, with grooves having various outlines so as to increase the mixing effect. None of those known devices however facilitates the circulation by utilizing the laws of reflection of particular curves as applied to of an elliptical or parabolic profile.

The described apparatus may be employed for many industrial operations for instance for the production of caustic soda or for the hydrolysis of neutral fats or oils by means of a lipase, for the saturation with ammoniac 'gas and the carbonation of the brine in the production of the soda by the ammoniac process and for many other opera- I tions necessitating the production of mixtures or of reactions. In the first operation hereinbefore indicated a lime milk is introduced into the apparatus, the circulation of which in the first cell has for its object to maintain the homogeneity. A solution of carbonate of soda is afterwards introduced in one or in manyof the following cells through the inlet openings 23 suitably arranged so asto secure a complete reaction with the lime milk. The gas which has been produced (carbonic-anhydride) escapes in this case, either through the outlet opening 26-28, or through one of the inlets 23 used as outlet apertures.

1n the second case the hydrolyzing action is produced by the action of an organic ferment in an acidulated emulsion of water in\ a neutral fat or oil. To this end, the neutral fat or oil diluted sulfuric acid and the lipase of castor oil seeds previously prepared, are introduced in the apparatus in suitable proportions. The emulsion in the mass of which the lipase is uniformly divided, is received at the outlet. in a special vessel where hydrolysis takes place in the known conditions.

. In the third mentioned case a concentrated or even sursaturated brine is introduced in the device. The circulation in'the first cell avoids any crystallization bythe eventual pulverization of the crystals in formation. Ammonia is introduced into the second cell and the reaction begins and is completed in the following cells so as to secure a saturation, as perfect as .possible, of the brine. The carbonic anhydride of the lime kilns is introduced in the fourth cell for the first carbonation. The solution is afterwards enriched in the following cell by a fresh solution of chloride of sodium or eventually by sodium chloride in dust so as to avoid the dilution. The carbonation is then set forth in the following cell by an admission'of pure carbonic anhydride obtained by the calcination of the bicarbonate. 'At the outlet of the apparatus, a liquid rich in chlorhydrate of ammonia is collected. This liquid holds in suspension the bicarbonate of 1. A mixer comprising a mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is of conical curvature in cross section, a rotating shaft passing through said chamber substantially coincident with its axis, a radial stirrer upon said shaft within said chamber, and inlet and outlet ports in the opposite side walls of the chamber.

2. A. mixer comprising two mixing chambers in axial alignment, and separated by a partitionwall having a substantially concentric aperture therethrough, the surfaces of the chambers being symmetrical about an axis the radial outer portion of which is of conical curvature in cross section, a rotary shaft passing through said chambers substantially coincident with their axis, radial stirrers upon said shaft and within said chambers,

.an inlet port in the side wall of one of said chamber, the path' of travel of the stirrer containing the locus of the foci of the conical sections of the surface of the chamber,

and inlet and outlet ports in the opposite side walls of the chamber.

4. A mixer comprising a mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is a plurality of intersecting conical curves in cross section, a rotating shaft passing through said chamber substantially coincident with its axis, a radial stirrer upon said shaft within said chamber, and an inlet and outlet port in the opposite side walls of said chamber. A

5. A mixer comprisinga mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is a plurality of intersecting confocal conical curves in cross section, a rotating shaft passing through said chamber substantially and outlet port in the opposite side walls of said chamber.

6. A mixer comprising a mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is an intersecting parabola. and hyperbola in cross section, a rotating shaft passing through said chamber substantially coincident with its axis, a radialstirrer upon said shaft within said chamber and an inlet and outlet port in the opposite walls of said chamber.

7. A mixer comprising a mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is an intersecting parabola. and hyper-bola in cross section, a rotating shaft passing through said chamber substantially coincident with its axis, a radial stirrer upon said shaft within said chamber, and an inlet port in the side wall of parabolic section and an outlet port in the opposite wall vof said chamber.

8. A mixer comprising a mixing chamber the surface of which is symmetrical about an axis and the radial outer portion of which is a plurality of intersecting conical curves in cross section, a rotating shaft passing through said chamber substantially coincident with its axis, a radial stirrer upon said shaft within said chamber, the path of travel of said stirrer containing the locii of the focii of the curved sections, and an inlet and outlet port in the opposite walls of said chamber.

9. A mixer comprising two mixing chambers in axial alignment, and separated by a partition wall having a substantially concentric aperture therethrough, the surface of the chambers being symmetrical about an axis the radial outer portion of which is a plurality of intersecting conical curves in cross section, a rotating shaft passing through said chambers substantially coincident with their axis, radial stirrers upon said shaft Within said chambers, an inlet port in the side wall of one of said chambers and an outlet port in the side wall of the other of said chambers, said inlet and outlet .ports being in the side walls o posite the partition wall.

In testimony whereof I have afiixed my signature.

GASTON SIDOINE PAUL de BETHUNE. 

